NEW YORK (Reuters) – U.S. prosecutors on Wednesday said the multiplatinum R&B singer R. Kelly deserves to spend more than 25 years in prison after being convicted of sex trafficking. In a filing in Brooklyn federal court, prosecutors said the 55-year-old Kelly exploited his stardom over a quarter century to lure women and underage girls for sex, demonstrating a “callous disregard” for his victims and showing no remorse. “Indeed, the defendant’s decades of crime appear to have been fueled by narcissism and a belief that his musical talent absolved him of any need to conform his conduct – no mat…